SNRNP70 and arthritic joint disease: In addition to muscle involvement, SSc patients with anti-U1RNP antibodies were younger at disease onset (120, 125, 131, 154) and presented more frequently with ILD (153, 156), PAH (123, 125), arthritis (125, 131, 153, 154) and limited skin involvement (120, 154) when compared with anti-U1RNP negative patients.